The present invention is directed to polymer compositions. More particularly, the present invention is directed to polymer compositions obtained by ring-opening metathesis polymerization of functional norbornene monomers.
Cycloolefin polymers (e.g. norbornene-based polymers) and copolymers have received a great deal of attention in recent years. They have found application in dielectric, optical, and photolithographic applications. In addition, the utility of these materials as engineering thermoplastics has been explored. As such, new cyclic olefin copolymers and catalysts for the efficient preparation of cyclic olefin polymers are constantly being sought.
The addition polymer of norbornene, i.e., polynorbornene or poly(bicyclo[2.2.1]hept-2-ene, was described in U.S. Pat. No. 2,721,189. In this patent, two types of norbornene polymers were prepared. The first polymer was prepared by the addition polymerization of norbornene giving a fully saturated cyclic olefin polymer. 
The second polymer was formed by xe2x80x9cRing-Opening Metathesis Polymerizationxe2x80x9d (ROMP) giving an unsaturated polymer backbone. 
Throughout the years, work in many academic and industrial institutions have led to the development of ring-opening metathesis polymerization catalysts that are tolerant of functional groups. Most notably, are the molybdenum and ruthenium complexes that Schrock and Grubbs have developed (U.S. Pat. No. 4,681,956; U.S. Pat. No. 4,883,851; WO 96/04289). A variety of polymers with pendant functional groups have thus been prepared by ROMP. Further processing of the unsaturated polymers has been attempted in order to achieve materials with better properties. Physical blends (WO 93/06171) and chemical modification of the polymer structure by hydrogenation (U.S. Pat. No. 5,115,037), photolysis (EP 904767 A2) and others (U.S. Pat. No. 5,603,985) are all examples illustrating technologies involved in the making of ROMP polymers.
Despite all advances in the new materials prepared by ROMP, there however remains a need to polymerize monomers with functional groups, such as epoxides and dioxalanes, which allow further chemical reactions to give polymers having desired physical properties.
The present invention relates to a polymer composition having the formula:
xe2x80x94[A]Sxe2x80x94[B]Txe2x80x94
wherein A is a monomer repeat unit derived from one or more monomers selected from the group consisting of: 
and B is a monomer unit derived from one or more functional norbornene monomers selected from the group consisting of: 
wherein
R7a and R7b are independently selected from H, hydrocarbyl, substituted hydrocarbyl, fluoroalkyl;
R8a and R8b are independently selected from H, hydrocarbyl, substituted hydrocarbyl, fluoroalkyl, C(O)xe2x80x94R9;
R9 is hydrocarbyl or substituted hydrocarbyl;
R5a and R5b are each independently H, hydrocarbyl, halogen, halohydrocarbyl, heteroatom connected hydrocarbyl or heteroatom connected substituted hydrocarbyl;
R6a and R6b are each independently H, hydrocarbyl, halogen, halohydrocarbyl, heteroatom connected hydrocarbyl or heteroatom connected substituted hydrocarbyl;
R5a-b and R6a-b may be taken together to form a ring, and S and T represent the mole fraction of the respective monomer unit and sum to one with the proviso that T greater than O; and k=0-3 and j=1-6.
The present invention is further a process for preparing functionalized polymers comprising the ring opening metathesis of functional norbornene to form homopolymers of norbornene or copolymers of norbornene wherein at least one of the monomers is a functional norbornene. The copolymers may be random, alternating or block copolymers.
The present invention relates to polymers having the formula:
xe2x80x94[A]Sxe2x80x94 and xe2x80x94[B]Txe2x80x94
wherein A is a monomer repeat unit derived from one or more monomers selected from the group consisting of: 
and B is a monomer unit derived from one or more functional norbornene monomers selected from the group cosisting of: 
wherein
R7a-b is H, hydrocarbyl, substituted hydrocarbyl, fluoroalkyl;
R8a-b is H, hydrocarbyl, substituted hydrocarbyl, fluoroalkyl, C(O)xe2x80x94R9 where R9 is hydrocarbyl or substituted hydrocarbyl;
R5a-b and R6a-b are each independently H, hydrocarbyl, halogen, halohydrocarbyl, heteroatom connected hydrocarbyl or heteroatom connected substituted hydrocarbyl;
R5a-b and R6a-b may be taken together to form a ring, and S and T represent the mole fraction of the respective monomer unit and sum to one with the proviso that T greater than 0; and k=0-3 and j=1-6.
In one embodiment of the present invention, the polymers herein described are prepared by a process including a ring-opening metathesis polymerization of cyclic olefins using metal complexes containg a metal-carbon double-bond which can undergo metathesis with a carbon-carbon double bond present in the monomers. Complexes such as the Schrock-type molybdenum alkylidene or the Grubbs-type ruthenium carbene complexes are preferred catalysts used in this invention.
As means of an example, ring-opening metathesis polymerization of monomers A1 and B4 is illustrated to give a polymer I, where neither the stereochemistry or the nature of end groups are implied by the drawing: 
As used herein, the phrase xe2x80x9ca monomer repeat unit derived from one or more norbornene, substituted norbornene or functional norbornene monomersxe2x80x9d refers to the polymer product of the transition metal catalyzed ring-opening metathesis polymerization of said monomers as depicted by polymer I. It is understood that polymer I only depicts one combination of A1 and B4 monomers and that many other combinations of A1 and B4 are possible.
The polymers products described in this disclosure can be further hydrogenated to give a saturated backbone. For instance, polymerization of monomers A1 and B4 by ring-opening metathesis polymerization produces polymer I as illustrated above. Polymer I can then be hydrogenated to give a polymer with a polyethylene cyclopentane-type structure, polymer II, where neither the stereochemistry or the nature of the end groups are implied by the drawing: 
The polymers described in this disclosure can be further hydrolized to give pendant hydroxy moieties. Polymerization of monomers A1 and B4 by ring-opening metathesis polymerization will, upon treatment with strong acids, give a polymer containing hydroxyl group. Similarly, the formation of free radicals is also possible from epoxide-containing monomer units such as those originating from B2.
In ring-opening metathesis polymerization, one polymer chain is produced per active site. An acyclic olefin can be used as a chain-transfer agent. Addition of an acyclic olefin of formula III, shown below, allows improved control over the molecular weight of the polymer and over the processibility of the reaction mixture as compared to reactions that do not utilize chain transfer agents: 
wherein R10a and R10b are hydrogen atom, hydrocarbyl, and substituted hydrocarbyl.
In this disclosure, symbols ordinarily used to denote elements in the Periodic Table take their ordinary meaning, unless otherwise specified. Thus, N, O and S stand for nitrogen, oxygen and sulfur, respectively.
A xe2x80x9chydrocarbylxe2x80x9d group means a monovalent or divalent, linear, branched or cyclic group which contains only carbon and hydrogen atoms. Examples of monovalent hydrocarbyls include the following: C1-C20 alkyl; C1-C20 alkyl substituted with one or more groups selected from C1-C20 alkyl, C3-C8 cycloalkyl, and aryl; C3-C8 cycloalkyl; C3-C8 cycloalkyl substituted with one or more groups selected from C1-C20 alkyl, C3-C8 cycloalkyl, and aryl; C6-C14 aryl; and C6-C14 aryl substituted with one or more groups selected from C1-C20 alkyl, C3-C8 cycloalkyl, and aryl; where the term xe2x80x9carylxe2x80x9d preferably denotes a phenyl, napthyl, or anthracenyl group. Examples of divalent (bridging) hydrocarbyls include: xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2xe2x80x94, and 1,2-phenylene.
A xe2x80x9csubstituted hydrocarbylxe2x80x9d refers to a monovalent, divalent, or trivalent hydrocarbyl substituted with one or more heteroatoms. Examples of monovalent substituted hydrocarbyls include: 2,6-dimethyl-4-methoxyphenyl, 2,6-diisopropyl-4-methoxyphenyl, 4-cyano-2,6-dimethylphenyl, 2,6-dimethyl-4-nitrophenyl, 2,6-difluorophenyl, 2,6-dibromophenyl, 2,6-dichlorophenyl, 4-methoxycarbonyl-2,6-dimethylphenyl, 2-tert-butyl-6-chlorophenyl, 2,6-dimethyl-4-phenylsulfonylphenyl, 2,6-dimethyl-4-trifluoromethylphenyl, 2,6-dimethyl-4-trimethylammoniumphenyl (associated with a weakly coordinated anion), 2,6-dimethyl-4-hydroxyphenyl, 9-hydroxyanthr-10-yl, 2-chloronapth-1-yl, 4-methoxyphenyl, 4-nitrophenyl, 9-nitroanthr-10-yl, -CH2OCH3, cyano, trifluoromethyl, and fluoroalkyl. Examples of divalent (bridging) substituted hydrocarbyls include: 4-methoxy-1,2-phenylene, 1-methoxymethyl- 1,2-ethanediyl, 1,2-bis(benzyloxymethyl)- 1,2-ethanediyl, and 1-(4-methoxyphenyl)- 1,2-ethanediyl.
A xe2x80x9cheteroatomxe2x80x9d refers to an atom other than carbon or hydrogen. Preferred heteroatoms include oxygen, nitrogen, phosphorus, sulfur, selenium, arsenic, chlorine, bromine, silicon, and fluorine.
A xe2x80x9cheteroatom connected hydrocarbylxe2x80x9d refers to a group of the type E10(hydrocarbyl), E20H(hydrocarbyl), or E20(hydrocarbyl)2, where E10 is an atom selected from Group 16 and E20 is an atom selected from Group 15.
A xe2x80x9cheteroatom connected substituted hydrocarbylxe2x80x9d refers to a group of the type E10(substituted hydrocarbyl), E20H(substituted hydrocarbyl), or E20(substituted hydrocarbyl)2, where E10 is an atom selected from Group 16 and E20 is an atom selected from Group 15.
The term xe2x80x9cfluoroalkylxe2x80x9d as used herein refers to a C1-C20 alkyl group substituted by one or more fluorine atoms.
The term xe2x80x9chalohydrocarbylxe2x80x9d as used herein refers to a C1-C20 alkyl group substituted by one or more of fluorine, chlorine, bromine or iodine atoms.
The term xe2x80x9cpolymerxe2x80x9d as used herein is meant a species comprised of monomer units and having a degree of polymerization (DP) of ten or higher.
As used herein, the terms xe2x80x9cmonomerxe2x80x9d and xe2x80x9colefin monomerxe2x80x9d refer to the olefin or the other monomer compound before it has been polymerized; the term xe2x80x9cmonomer unitsxe2x80x9d refers to the moieties of a polymer that correspond to the monomers after they have been polymerized.
The term xe2x80x9cchain-transfer agentxe2x80x9d as used herein refers to a compound capable of reacting with the growing polymer chain at the metal-carbon double bond by metathesis, thereby cleaving off the polymer chain and generating a new initiator capable of polymerizing the monomers by ring-opening metathesis polymerization.
The term xe2x80x9cmetathesisxe2x80x9d herein used refers to the reaction between a metal-carbon double bond and a carbon-carbon double bond, leading to a new metal-carbon double bond and a new carbon-carbon double bond through the formation of a metallocyclobutane intermediate.
In some cases, it is advantageous to attach the catalyst to a solid support.
Examples of useful solid supports include: inorganic oxides, such as talcs, silicas, titania, silica/chromia, silica/chromia/titania, silica/alumina, zirconia, aluminum phosphate gels, silanized silica, silica hydrogels, silica xerogels, silica aerogels, montmorillonite clay and silica co-gels, as well as organic support materials such as polystyrene and functionalized polystyrene. (See, for example, S. B. Roscoe et al., xe2x80x9cPolyolefin Spheres from Metallocenes Supported on Non-Interacting Polystyrene,xe2x80x9d 1998, Science, 280, 270-273 (1998) the contents of which are incorporated herein by reference).
The present invention is explained in greater detail in the following non-limiting Examples.